KATHMANDU, March 31: The government has initiated a study for the construction of the main headwork and diversion structure of the Melamchi Water Supply Project at Sarkathali.

This decision comes in response to annual floods that have been damaging the existing headwork and diversion structure at the Melamchi’s point of origin, prompting the search for a safer alternative location.

Rajendra Pant, the spokesperson and engineer of the Melamchi Water Supply Development Committee, mentioned that constructing a headwork and diversion structure approximately 1 km from the Melamchi’s origin is considered suitable. The study suggests that for long-term sustainability, the Melamchi drinking water supply's headwork structure, currently situated at a high-risk disaster area, should be relocated.

"We are currently exploring the construction of a new headwork and diversion structure at a location known as Sarkathali, about 1 km from the Melamchi origin," Pant said.

Following the destruction of the headwork structure by floods in August 2023, which also damaged the access road and halted water distribution to Kathmandu, a technical and expert group from the Asian Development Bank (ADB) recommended relocating the headwork structure.

Prime Minister Pushpa Kamal Dahal inaugurated the resumed distribution of Melamchi water to the Kathmandu Valley on January 15, utilizing a temporary structure.

Expected to be costly

The relocation and construction of a new headwork for the Melamchi project are expected to be costly. Pant estimated that the cost of building a tunnel along with the headwork would exceed Rs 3 billion. "The preliminary estimate for relocating the main headwork to a new location is between Rs 3-4 billion," he stated, emphasizing the need for the headwork and tunnel to be constructed above the spring in a safe, spacious area for the long-term distribution of Melamchi water.

Difficult for Yangri and Larke rivers diversion

In the second phase, the plan is to combine 17 million liters of water each from the Yangri and Larke River projects into the same headwork structure. Consequently, the main headwork and diversions of Melamchi must be constructed in a robust and secure location. Currently, efforts to expand the access road for channeling the Yangri and Larke rivers are progressing rapidly. Project officials have expressed concerns that annual flood damage to the headworks complicates the process of directing water from the Yangri and Larke rivers into the tunnel.

The task of constructing access roads to both rivers is further complicated by the increasing flood risks. The areas of Melamchi-Vemathang, Indrawati, Helambu, and Ambathan are particularly vulnerable to floods and landslides.

Last rainy season's floods buried the headworks structure under 20 feet of debris. This debris, along with stones, gravel, and sand that entered the audit tunnel, was cleared away using a temporary structure. After floods in June 2021 severely impacted the spring area, water has been temporarily diverted to Kathmandu.

Although former President Bidya Devi Bhandari officially inaugurated the water distribution on March 14, 2021, annual floods have hindered consistent water supply to the Kathmandu Valley. With an investment exceeding Rs 30 billion from the Asian Development Bank (ADB) and the Government of Nepal, the Melamchi project is seen as a crucial initiative to meet the water needs of Kathmandu Valley residents.

 
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